1. Field of the Invention
This invention relates to a method for printing with dispersion dyes various synthetic fibers by a discharge or discharge resist process.
2. Description of the Prior Art
In German Pat. No. 10 86 209 printing pastes are described for the direct or discharge printing processes on textiles of new or regenerated cellulose, natural silk or linear polyamides. Dyestuffs employed for this process are vat and/or sulfur dyes. In addition to this "discharge resist" processes are known where either tin-(II)-chloride or the zinc salt of hydroxymethane sulfinic acid are used as discharging agents. The drawback of tin-(II)-chloride is that it releases hydrochloric acid during the dyeing process at temperatures above 100.degree. C. This results in pronounced corrosion in the steamers in which the imprinted goods are heat treated. The use of the zinc salt of hydroxymethane sulfinic acid is not without its detriments either since the dyestuffs which are required for the color printing of the good are stable for a limited amount of time only. This often results in the production of rejects.
German Pat. No. 27 53 696 describes a process which does not have these drawbacks, however, this process can be used only for "discharge resist" printing. In the "discharge" printing process, pre-dyed goods are used, that is, the dye for the background is already fixed. The pre-drying results in more uniform surfaces and is also advantageously used with knitted goods which pose particular padding problems for technical reasons.